AR-15, rifle to carbine stock conversion, reliability issues?

[T.Stahl]

The background:
I'm in Germany and contemplate a replacement for my HK SL8. Compared to 2003, when I bought my SL8, there is a growing supply of service-style semi-auto rifles. Naturally the HK41 has seen a revival in Germany, being made by a few small manufacturers (just not HK). There's a new AR-15 maker every year (SIG, Schmeisser, HK,...) and not just OberlandArms, which started it. We can even get FALs, M1As or Dragunovs.
And after considering a patriotic HK41-clone and the actually better designed FAL, I think I'll get an AR-15 after all.

Why?

Because what applies to cars that you plan to use everyday for a long time, also applies to guns:
Don't buy something exotic. Exotics are for collectors, not users. Get a volume model with a common engine from a large OEM. A model-engine-combo that, if they screwed something up during development, would hurt them really bad. Something that bores the mechanic. With lots of aftermarket accessories and cheap spare parts, 'cause it's just one of a million (and not one of 6500 as my current car ).

And because the AR-15 in .223 is becoming the VW Golf TDI of the semi-auto rifle world also in Germany, it's the one offered with the most variety.

My choice for a base gun is an OberlandArms OA-15 Black Label A4. It features:
- direct impingement (or more properly, gas-piston in the bolt-carrier)
- 20" bbl
- fixed stock
- fixed front sight carrier
- detachable carry handle

The question:
Can the conversion of an 20" AR-15 with a rifle-length gas system from a fixed rifle stock to a collapsible carbine stock configuration cause reliability issues?
I read the carbine buffer tube comes with a separate buffer spring and a short buffer.

Thank you!

[Quentin2]

You shouldn't have any issues swapping the rifle receiver extension/stock to the carbine RE/telescoping stock. I did exactly that with an ArmaLite 16" midlength gas using first the standard weight carbine buffer then moved to the heavier H buffer. (Which still cycled well, even with low powered ammo.) I'd expect your extra 4" barrel and rifle length gas would perform about the same as my setup.

I would try to find a milspec diameter RE and stock, unless the commercial diameter version is far more common in Germany. (Oh, you are correct that the carbine RE uses a different spring and buffer than the rifle.)

[Theohazard]

Rifle-length buffer systems tend to be softer shooting, have a lower cyclic rate, and are more flexible in terms of gas pressures than carbine-length systems.

Your rifle should run just fine with a carbine buffer system (especially if you use a heavier buffer), but if you want the benefits of a rifle system with the collapsibility of a carbine system, try the VLTOR A5 buffer system. It has a buffer tube that's a little longer than a carbine one and it has a very heavy buffer that's about half-way between the size of a carbine and a rifle buffer.

The A5 system was developed for the Marine Corps to replicate the performance of the rifle-length system but with a collapsible stock. My A5 system is amazingly flexible; it runs smoothly and reliability suppressed or unsuppressed with no over-gassing issues. My LGS's gunsmith borrowed my lower to test a pin-and-welded suppressed upper and it ran great. So he took the can off (he hadn't pinned-and-welded it on yet) just to see if my lower would run without extra pressure of the can (it was a short barrel with very short dwell time and therefore very low gas pressure with the can off). The A5 ran fine even without the suppressor attached.